Just over a week ago, on the night of Tuesday July 18, the military leadership of Hamas met in an apartment building filled with families to plan the latest round of attacks on Israel. Among them was Mohammed Def, a master terrorist who has for years planned attacks on civilians using the cover of innocent Palestinians as protection.

Today I received an email from the leadership of Oxfam drawing my attention to a press release . The Oxfam press release calls upon Tony Blair to demand an Israeli military police investigation into an allegation that on Monday July 17 Israeli soldiers used six civilians as human shields during a gunfight with armed Palestinians in northern Gaza.

In fact, Oxfam's source is an Israeli group called B'Tselem (B'Tselem is the Hebrew for "in the image of" God). The allegation must be investigated and, if proven, the perpetrators should be punished with the full rigour of the law, backed by public disapproval of this disgusting behaviour.

Disgusting though it is, however, I suppose one should not be totally surprised. After all, even British and US soldiers are capable of appalling acts - as we know from Iraq.

I have no quarrel with Oxfam's press release and would not wish to offer either justification or mitigation. What concerns me, however, is that Oxfam has not drawn my attention to press releases about Mohammed Def, about years of cynical Hamas exploitation of their fellow Palestinians by hiding their activities in the houses and apartment blocks of their fellow countrymen. Nor have I seen press releases linking many of the quite unacceptable civilian casualties in Lebanon to the tactic of hiding lethal missiles in basements and garages and turning a whole area of residential Beirut into terrorist headquarters.

I confess to not understanding much of the reaction in Britain to what is going on in Lebanon. I don't understand why Anthony Howard (on Any Questions) compared what he asserted was collective punishment being inflicted by Israel to "the behaviour of the Nazis towards it [sic] in world war two". I didn't understand the contributor on the same programme who suggested that Israel's bombing of Hizbullah bunkers in Lebanon would have been the equivalent of Britain bombing Dublin during the IRA terrorist campaign. The analogies are both silly and obscene.

How can I explain to myself this avalanche of criticism of Israel? Is it, perhaps, rooted in a feeling that Israel should behave according to different, higher standards than its enemies? I must confess that I expect Israel to behave according to the highest Judaeo-Christian ethical standards. But the inference that Islam does not share those values is patronising and offensive.

Is it perhaps that western intellectuals like Jews best when they are victims but cannot cope when they assert their rights to be free from terror in their own land? Is there something about the Jew - perhaps the way we have been treated by western Christian society over 2,000 years - that still makes others uncomfortable and determined to take every opportunity to point out that we are no better than anybody else. Believe me, we know we're not, and we don't want to be a permanent reproach.

Whatever the explanation for this latest outpouring of criticism, fair-minded liberals, those committed to justice and the values of western society, need to face up to what is really going on "out there".

We have witnessed the rise of a perversion of Islam, a fanatical Shia fundamentalism that does not share our values - yours, mine or Islam's. Whether in London or New York, Kabul or Bali, Beirut or Haifa, it claims a truth that permits any act of barbarity, however savage. At this time, one of its key bastions is Iran, and it is quite clear that Iran - in arming Hizbullah, in supporting other Islamic fundamentalist groups, in endorsing Osama bin Laden and in developing nuclear weapons - rejects out of hand everything that you and I stand for.

It is true that there is a virulent anti-semitism associated with the regime in Tehran. That's why the president has just said that he would be happy for all Jews to come to Israel, so that he can wipe out the Jewish people in one fell swoop without having to pursue diaspora Jewry to the four corners of the earth. But if you think that only Jews and Israel are on the Iranian agenda, you must be completely daft. For Jews and Israel are simply on the frontline, at the point where the tectonic plates of the west and Islamic fundamentalism meet.

You may well argue that western foreign policy - globalisation, exploitation - is to blame. But I think what we are witnessing is an episode in a long history of conflict between the Muslim and western worlds that goes back to the very birth of Islam and for which both the (Christian) west and the Muslim world must take responsibility.

You may even think that the existence of Israel complicates the situation, and it would have been better had the United Nations not taken its fateful decision in May 1948. We Jews are used to being a complication and a nuisance.

However, what you must not dispute is the danger in which we all stand. There is a fanatical, implacable enemy out there, and it rejects the fundamental values by which we try to live and on which we stand. It is an enemy bent on reshaping the Middle East; an enemy that could, ultimately, hasten the decline of the west and the rise of China.

It is also a very astute opponent. I have no doubt that Hizbullah/Iran suckered the inexperienced Israeli government into its response in order to deflect G8 discussions of Tehran's nuclear plans. I have no doubt that Syria and Iran knew that Israel's response would bring about civilian casualties, a humanitarian disaster in Lebanon and the wave of international concern and criticism of Israel.

Let me repeat: people are absolutely right to point to Israel's failures to abide by the highest values. But to allow the western conscience to be manipulated and to avoid seeing what is really going on - that would be a failure of gigantic proportions with consequences not just for Israel but for the long-term future of western civilisation, which with all its many faults is infinitely preferable to anything else currently on offer.